The 1947 partition of British India created the independent states of India and Pakistan, splitting the provinces of Punjab and Bengal along a boundary drawn by British lawyer Cyril Radcliffe. In the following months, an estimated 10–20 million people crossed the new borders in one of the largest and most rapid mass migrations in history, as Hindus and Sikhs moved toward India and Muslims toward Pakistan. The migration was accompanied by widespread communal massacres, abductions, and sexual violence; death toll estimates range from roughly 200,000 to 2 million. The event permanently reshaped the demography of South Asia and set the stage for enduring India-Pakistan tensions, including over Kashmir.
British India was partitioned into the new dominions of India and Pakistan along the Radcliffe Line; Hindus, Sikhs, and Muslims crossed the new borders amid widespread communal violence
The 1941 census of India recorded about 28.4 million in Punjab and 60.3 million in Bengal, roughly 89 million in the provinces actually divided by the Radcliffe Line, out of 389 million in British India as a whole. The 1941 religious counts are known to have been inflated by communal mobilisation and are treated with caution by historians.
Britannica states that estimates of the number who died during Partition range from 200,000 to 2,000,000, and elsewhere in the same article that as many as 2,000,000 were slaughtered in communal massacres. There was no census-based reconciliation: the lower figures derive from contemporaneous British and provincial administrative reporting, the higher from later demographic reconstruction and from Indian and Pakistani national historiography, each of which tends to emphasise the suffering of its own communities. Britannica notes Sikhs suffered the highest casualties relative to their numbers, and that some 15 million people crossed the new borders.
Britannica documents communal massacres, ambushes of refugee columns and trains and the burning out of border villages; the abduction and sexual violence against tens of thousands of women is documented in the Indian and Pakistani governments' own 1947-49 recovery programmes under the Abducted Persons (Recovery and Restoration) Act and in the oral-history research of Urvashi Butalia and Ritu Menon.
Pakistan, India, Bangladesh